There is a well-known lens barrel for an image taking lens attached to a shooting device of an electronics camera and so forth. By the way, with respect to a solid-state imaging device (CCD and so forth) and a CPU built in the shooting device, heating value thereof increases as its performance is advanced. Due to this, harmful effects are sometimes caused. For example, operation becomes unstable, a processing speed lowers, and life is shortened. Consequently, it is necessary to prevent temperature rise by efficiently radiating the heat of the solid-state imaging device and so forth.
It is considered that the lens barrel has a radiation effect to radiate the heat of the solid-state imaging device and so forth. For instance, in a known semiconductor laser module used for optical communication, the inside thereof is provided with a heat sink to radiate the heat emitted from the semiconductor laser (see Japanese Patent Laid-Open Publication No. 8-179170). Meanwhile, a known color-image forming device has an electric heater, a cooling pipe and a propeller fan for the purpose of keeping an image-forming optical system in a proper temperature (see Japanese Patent Laid-Open Publication No. 8-234524).
The semiconductor laser module described in the above-noted Publication No. 8-179170 contains the heat sink. However, it is impossible to dispose a heat sink inside the lens barrel of the taking lens, since the lens barrel becomes large. In the color-image forming device described in the above-noted Publication No. 8-234524, the copling pipe is drawn out of a support member of the optical system, and the propeller fan is used. Thus, it is impossible to adopt this manner to the lens barrel of the taking lens.